"Estudo e Dimensionamento de um Conversor Dual Active Bridge para Microrredes CC em Baixa Tensão"

Bernardo Mendes Micaelo André

Key information

Authors:

Bernardo Mendes Micaelo André (Bernardo Mendes Micaelo André)

Supervisors:

José Fernando Alves da Silva (José Fernando Alves da Silva)

Published in

November 11, 2022

Abstract

The growing concern caused by the increase of electricity demand, raises the decentralization of the electro-producing sector in smaller distributed generation units, giving rise to the concept of microgrid. In this context, DC (Direct Current) microgrids have stood out compared to AC (Alternated Current) microgrids, as they provide better levels of operating efficiency and do not require phase and frequency control systems. To mitigate the imbalances caused by the difference in electricity generation and demand, the usage of energy storage systems becomes prominent. The connection of these systems to the DC microgrid is ensured by electronic power converters that allow bidirectional power flow control. This thesis presents the project design of an isolated bidirectional DC-DC converter based on Dual Active Bridge (DAB) topology, which serves as an interface between a DC bus of a low voltage DC microgrid, with an energy storage system. It is proposed a control system that allows the stabilization of the battery supply voltage level, based on the coupling of two cascaded linear controllers, with an optimized modulation strategy based on the inductor current stress minimization with Dual Phase Shift modulation (CSO-DPS). CSO-DPS is derived based on the application of Lagrange Multiplier's Method (LMM) to the equations that translates the behavior of Dual Phase Shift modulation. The global system is then simulated in Matlab/Simulink, and the results obtained are analyzed and discussed considering a case study.